Answer:
2250N
Explanation:
W= mg,
where W= weight
m= mass
g= acceleration due to gravity
Given that the body is 90kg, m= 90kg.
Acceleration due to gravity of planet
= 2.5(10)
= 25 m/s²
Weight of body on planet
= 90(25)
= 2250N
*Mass is the amount of matter an object has and is constant (same on earth and the planet).
Answer:The frequency of the echo is slightly decreased
Explanation:
Given
speed of boat 
cliff is
away
when boat is still , suppose t is the time taken by the echo to reach observer on the boat
But as soon as boat starts moving the distance between cliff and boat decreasing and time for echo to reach observer also decreases
and we know 
therefore frequency of the echo slightly decreased.
Answer:
The force needed is the weight of the rock minus the buoyant force.
Explanation:
Answer:
we got time and velocity over time.
so the distance is again the area underneath the graph
for a triangle with known base and height it's
4*10 / 2
distance traveled is 20
deceleration occurs when velocity decreases. that happens from t=2 till t=4
in 2 time-units we loose 10 units of velocity, so we decelerate by 5 units per 1 time
a (from t=2 to t=4) = -5v/t
Satellite. think of the moon.
Hope this helps!
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